1. Field of the Invention
The present invention relates to a rotary contactless connector and a non-rotary contactless connector. More particularly, the present invention relates to a novel improvement for implementing contactless optical communication type single-channel or multi-channel signal transmission by using the rotary contactless connector and the non-rotary contactless connector. In the case of the rotary contactless connector, a rotor of a rotary transformer is equipped with a rotating-side light emitting or light receiving element, and electric power from an external source is supplied through the intermediary of the rotary transformer to an electric circuit for driving and controlling the rotating-side light emitting element or light receiving element. In the case of the non-rotary contactless connector, the electric power from an external source is supplied through the intermediary of a transformer to an electric circuit for driving a light emitting element or a light receiving element at a power-supplied side.
2. Description of the Related Art
Hitherto, signal transmission between a stationary-side unit and a rotating-side unit has been effected by connecting, for example, a rotating-side unit mounted on a gimbal mechanism having a plurality of rotating shafts or a single-shaft rotating platform and a stationary-side unit by using a rotary joint or slip ring and a contact connection type connector, and eventually by direct coupling to the contact connection type connector.
Great efforts have been made to obviate the need for the use of wiring, and the contactless type data transfer has become significantly easier owing to the progress in the recent infrared communication technology. However, it has been difficult to achieve supply of electric power from a stationary unit to a rotating unit in a contactless mode, and the need for the wire for supplying power still remains, making it difficult to completely eliminate wiring. Furthermore, contactless type data transfer using an optical connector or optical coupler that combines a light emitting member and a light receiving member has also been having a similar difficulty.
The conventional transmission of signals between a stationary unit and a rotating unit described above has been presenting the following problems.
Specifically, the connection method based on a contact type connector and the direct coupling wiring method for connecting a stationary unit and a rotating unit inevitably produce parasite drag generated due to the twist or rigidity of wiring even when only rotary motion of a finite angle is involved.
The rotary joint or slip ring method has been posing such problems as larger sizes, higher cost, and lower environmental resistance although it has less likelihood of the occurrence of the parasite drag attributable to the twist or rigidity of wiring.
Furthermore, use of a modulation type infrared communication device for transmitting a required quantity of data to be transmitted or received by multiple channels would lead to a lower data transmission rate with resultant reduced transmission capacity and higher cost. Inevitably using a non-modulation method to avoid the above-mentioned problem, in turn, has been posing the problem of interference among channels.
The present invention has been made with a view toward solving the above problems, and it is an object of the present invention to provide a rotary contactless connector and non-rotary contactless connector adapted to perform optical communication type single- or multi-channel signal transmission in a contactless condition.
In the rotary contactless connector for signal transfer between a stationary unit and a rotating unit, a rotating-side light emitting element or light receiving element is mounted on a rotor or a connected member with its rotor to construct a data communication system for transmitting or receiving signals to or from the rotating unit. An electric power is supplied from the stationary unit through the intermediary of the rotary transformer.
For the non-rotary contactless connector to transfer signals between two faced units that are not in contact and whose relative faced positions remain unchanged, a light emitting element (or a light receiving element) is mounted on one of the two units or their connecting members, and a light receiving element (or a light emitting element) is mounted on the other of the two units or its connected members such that they oppose each other, thereby making up a data communication system to transfer signals between two units. For a power system, a transformer that has an extremely small gap between the two non-contacting units is formed to supply electric power from one to the other.
According to one aspect of the present invention, there is provided a rotary contactless connector including a rotary transformer composed of a rotor that has a rotary transformer winding and an annular stator that is concentric with the rotor and has a stator transformer winding, a rotating-side light emitting element or rotating-side light receiving element provided on the rotor, and a stationary-side light emitting element or a stationary-side light receiving element that is fixedly disposed to oppose the rotating-side light emitting element or the rotating-side light receiving element, wherein electric power is supplied to the rotor through the rotary transformer.
Preferably, a nonmagnetic and non-magnetized bearing is provided between the rotor and the annular stator.
Preferably, an electric circuit for driving the rotating-side light emitting element or the rotating-side light receiving element is provided, and electric power is supplied to the electric circuit through the rotary transformer.
Preferably, the rotating-side light emitting element or the rotating-side light receiving element is provided at the central position of the rotor.
Preferably, a plurality of the rotating-side light emitting elements or the rotating-side light receiving elements are provided at the concentric circumferential positions other than the central position of the rotor.
Preferably, a plurality of the rotating-side light emitting elements or the rotating-side light receiving elements are provided in the radial direction of the rotor.
Preferably, the electric circuit is provided in the rotor.
To perform optical communication, a power output of the rotary transformer is divided into two outputs, one being directly coupled to the electric circuit, while the other being coupled to the electric circuit through the intermediary of storage means composed of a capacitor or a storage cell.
Preferably, the intermediary of storage means or the directly coupling line can be obviated with the specific requirement for electric power.
According to another aspect of the present invention, a non-rotary contactless connector is provided composing of two stationary members. These stationary members have the similar components except the electric parts between the transformer output and the electric circuit as below. One stationary member is the supplied side of the electric power by the name of first. The other stationary member is the supplying side of the electric power by the name of second. These stationary members each have a transformer winding, respectively. The transformer winding of the first stationary member is disposed to face with the transformer winding of the second stationary member for making up magnetic path. The electric power is supplied from the second to the first by means of a transformer.
These stationary members have optical-electric elements, respectively. The optical-electric elements of a first stationary member are disposed to oppose to the optical-electric elements of a second stationary member for an optical communication. The optical-electric element is composed of light emitting elements or light receiving elements. An optical communication is performed between the first and second by means of the optical-electric elements. The electric power for driving the optical-electric elements on the first stationary member is supplied through the electric circuit from a first transformer output. The electric power to optical-electric elements on the second stationary member is supplied from an outside power unit.
Preferably, a power output end of the first transformer winding is divided into two outputs, one being directly coupled to the electric circuit, while the other being coupled to the electric circuit through the intermediary of storage means composed of a capacitor or a storage cell.
Preferably, the intermediary of storage means or the directly coupling line can be obviated with the specific requirement for electric power.